Andrew krieger



(No Moae1.)' A

- A. KRIEGBR.

INSERTED TOOTH SAW.

No.v555,'518. i Patented Mar. 3., 1896.

UNITED STATESY PATENT rricn.

ANDREW KRIEGER, OF INDIANAPOLIS, INDIANA.

INSERTED-TOOTH SAW.

SPECIFICATION forming part of Letters Patent No. 555,518, dated March 3, 1 896.

, Application led June 24,1895. Serial llo. 553,809. (No model.)

To a/ZZ whom t may concern:

Be it known that I, ANDREW KRIEGER, a citizen of the United States, residing at Indianapolis, in the county of Marion and State of Indiana, have invented certain new and useful Improvements in Inserted-Tooth Saws 3 and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification. p

My invention relates to that class of saws which have tooth sockets'or recesses cut and milled directly into the saw-blade and teeth secured therein by rivets or similar means; and it consists of a certain new and novel design of construction embracing valuable features whereby various advantageous improvements are obtained, and will be more fully described hereinafter.

In that class of saws referred to, and especiallyin very thin circular and band saws, recesses for insertible teeth must be cut so shallow that the bottom of socket shall not penetrate below a certain depth into the blade, so that the necessary stiffness of the blade is not destroyed. The operation of securing teeth in such recesses or sockets requires most careful and skillful work, in'order to avoid straining and distorting the cuttingedge of the saw-blade to such a degree as to uniit it for straight and true cutting. Even when the greatest caution is exercised the blade is sometimes so distorted as to require the skillful use of the hammer to restore the tension and remove the distortion. In such saws it is also necessary that they have a great number of teeth, 'the sockets for which as heretofore constructed require several operations in cutting and milling, together with tedious handwork to fit the teeth to same, all of which increase the cost of such saws to an extent that prevents their practical and economic use.

My object is to provide an inserted-tooth saw of such perfect'design as to eliminate the defects-and objections referred to, and with this in view I have constructed a saw that is simple in design, maybe manufactured at a minimum cost, and is efficient, reliable, and durable in use. To attain this end, I construct a saw-blade having a perforation immediately below the base of each projection, which forms theforward part of the toothsocket, and extending from a point below the lowest part of the throat backward to a point below the bottom of tooth-socket, the perforation being oblong with rounded ends and lying approximately parallel with the line of saw-blade. This perforation permits the tooth to be clamped in the socket and provides a limited amount of elasticity for the, forward part of the tooth-socket, whereby it may yield instead of the jaw at back of tooth being forced out of alignment. In thus yielding to the pressureexerted by the act of riveting or clamping the tooth the clamp or forward part of socket does not throw out of alignment or strain the saw-blade below, as the base is given sufficient iiexibility to obviate this, while at the same time its support is stiff and firm enough to securely hold the tooth independently of the direct support of the blade below.

' The perforation is cut into the blade by a punch simultaneously with the cutting of the tooth-socket above, the socket being finished complete in one operation to receive the tooth without further fitting, thereby securing absolute accuracy and interchangeability of teeth. By this improvement it is made possible to use inserted-tooth saws at a cost little, if any,greater than that of solid saws, no matter how many teeth are required.

A further advantage possessed by my invention is the ease and accuracy with which a band-saw embodying my improvements passes over the pulleys, the perforations removing the otherwise stiffness caused by rigid clamping.

Referring to the drawings, Figure 1 represents a side view of a portion of a saw-blade, showing one inserted tooth and an open socket and the perforation C. Fig. 2 is a plan or edge view. Fig. 3 is an enlarged side view of tooth, and Fig. 4 a perspective view of same. Fig. 5 is a sectional view of toothshank and saw-blade on the line fr Qc, Fig. l.

The saw-blade A has cut into it recesses or sockets a for the reception of teeth. The walls of the recesses are squareedged or rect--v Icov angular instead of having the usual tongues. O11 the lower front wall of socket a is a shoulder e to correspond with an opposing shoulder e' on a tooth. Further up in the front wall is a notch CZ to correspond to a like notch 0 in a tooth. Immediately below the toothclamp m is punched a perforation C, leaving bctweenit and thc clamp a narrow strip at j" and y1', which is thereby made elastic and receives all the strain of the clamping of the tooth without 'springing the saw-blade. The tooth-shank B' is of the usual straight and grooved form on the back. lts front is squareedged and has a notch o `to correspond with a like notch (Z in front wall c of socket for the pu rposc of receiving a rivet p to lock the tooth in its seat. At the lower front edge of tooth is a shoulder e, and from this point down the tooth tapers to the bottom. The object of this shoulder and taper isy to provide a bearing-point for the tooth, while clearing at the round bottom1 r in recess. It also admits of the tooth having its rest and notch for the rivet on the same edge, which simplifies the forging of thc tooth and insures the absolute and accurate distance between those parts. This is of great importance on account of the several teeth in their front bearing-points affecting the evenness of the cutting-edge.

The extreme lower end r does not bear in the recess f, which requires no accurate trimming of the end of tooth. The shoulder n clears top n of clamp. That edge zy of the saw-blade having the sockets cut therein is ground somewhat thinner to the depth of the recesses.

The tooth-shank B is of the thickness of the body of the saw-blade A, and when inserted into the recess the rear grooved portion k engages the square wall b of the socket a, which, being thinner than the extreme width of groove in back of tooth, enters into the same and holds the tooth laterally. After the tooth is inserted a rivet p is entered into the opening formed by the notches in tooth and recess and riveted down until the tooth is firmly held laterally and vertically.

The saw-blade A is in no way distorted by the clamping or riveting operation, as the strain is entirely absorbed by the narrow parts at t and f below the clamp and between it and the perforation.

It will be observed by the above description that saws made according to the above plan have all the advantages of such saws in which interlocking pieces are employed, and yet are so cheap and simple in construction that in case of accidental breakage the expense of cutting a new set of tooth-recesses is done at a triiling cost as compared with the expensive operation of milling and filing, which has been the practice heretofore.

Having described my invention, what l claim, and desire to secure by Letters Patent of the United States, is-- 1. In a saw-blade having teeth inserted into suitable sockets cut therein and held by means of a clamp forming the front wall of socket, that is integral with said saw-blade assisted by rivet or locking-pin, the combination of the spring-clamp m due to the elongated narrow perforation C having rounded ends, by which the root or base of said tooth-clamp is separated, where lits thrust exerts a strain in the direction of the blade, from the said blade, the clamp thereby being supported iiexibly and attached at two narrow parts f and v1 integral with the blade, adjacent to the ends of `said perforation and approximately equidistant each way from thecenter or body of said clamp, for the purpose of relieving the body of the blade below each tooth from radial and lateral distortion consequent to forcing a tooth into socket and against said clamp; the shoulder e in each of said sockets and an opposing bearing-shoulder e' near bottom of forward side of shank of each of said teeth, said slioul'- ders together forming a support and gage to insure the uniform length of said teeth; the rectangular rear wall b of tooth-socket extending from top to bottom of same; the rectangular wall c; the beveled portion of sawblade forming rear of socket or support for tooth, said bevel being on both sides of sawblade, greatest at corners of rectangular wall b and diminishing gradually rearward, substantially as and for the purpose shown and described.

2. In a saw-blade having insertible teeth, the rear portions of which are grooved and sockets cut into the blade into which the teeth are secured, the combination of the shoulder e/ on the forward side near bottom of shank of tooth B; the shoulder c in forward side of socket a; the rectangulairear wall l) of said sockets; the tapering portion of blade below 7L extending from top of jaw to bottom of socket and receding rearward; the saw-blade having a perforation C below clamp m and extending approximately parallel longitudinally with the saw-blade, substantially as and for the purpose shown and described.

3. In a saw-blade having tooth-sockets eut therein and removable teeth inserted in said sockets, the combination of the rear rectangular wall l) constructed thinner than the said tooth, in bearing contact with a groove 7.: at rear of said tooth, said socket and tooth having a suitable rivet or locking-pin in front, the shoulder e/ on forward part near bottom of shank of tooth B; the bearingshoulder c in forward side near bottoni of' socket a to support the said tooth B and provide a gage by which all the teeth of a saw must be of uniform length, substantially as shown and described.

4. ln a saw-blade having inserted teeth in sockets cut into the blade the forward wall of said sockets being a springclamp due to the perforation C lying approximately parallel longitudinally with the saw-bladc, substantially as and for the purpose shown and deJ scribed.

5. In an inserted-tooth saw, the combina- IOO IIG

tion of a tooth-sockethaving the two sides or Walls thereof parallel vertically and the bearing-surfaces thereof rectangular to the sides of saw-blade, the shoulder e near bottom of said socket, the tooth-clamp m c omprising the forward part of socket provided with flexible base by being attached integrally at two narrow parts f and i while its central bottom portion is separated from the blade by means of the perforation C through said saw below said tooth-clamp to provide resiliency thereto, a cutting-tooth having the shank thereof in conformity with said socket except that the back of shank has longitudinal groove, while the remaining bearing-surfaces are rectangular to the sides of shank and side of sawblade when inserted, substantially as and for the purpose shown and described.

6. In a saw-blade having tooth-sockets cut into the blade and insertible teeth having zo grooved backs, the slightly-tapering part of blade hat rear of socket extending downward to bottom of same, whereby the blade is thinner where the rear wall of socket engages the groove in back of tooth-shank, substantially 25 J. F. IWICKEE, M. MCDONALD. 

